The subject invention is in the field of handles for hand held and operated equipment, including, for examples, hammers, saws, typewriters and computer key boards. Specifically it is in the field of handles intended to relieve physical stress in the wrist joint during use of hand-held equipment. More specifically, it is in the field of handles for tools which must or may be used without action of the wrist joint of the hand holding the hand-held equipment. 2. Prior Art
The patents listed below are a sampling of the prior art in this field, the closest prior art known to the inventor of the subject invention. U.S. Pat. Nos.:
______________________________________ 2,353,557 4,570,340 2,672,685 4,924,571 4,117,593 4,924,924 ______________________________________
The Arm Controlled Power Cutter of U.S. Pat. No. 4,924,571 and the Hand-held Turning Tool System of U.S. Pat. No. 4,924,924 both embody the principle feature of the subject invention: i.e. structure which bridges the wrist joint for the purpose of reducing the physical forces applied to and required of the joint relative to the bending moment applied by use of a particular tool or implement. This feature is not particularly applicable to tools or implements which require flexing of the wrist joint, such as a hammer or a tennis racquet but it is particularly applicable to tools and implements which do not necessarily require flexing of the wrist joint, such as knives and hand gardening tools.
The usefuleness of a handle incorporating structure which bridges a wrist joint is significatly enhanced by having the handle readily and easily adaptable to use with a variety of tools and implements and to a variety of techniques of using any or all of the tools and implements. This is particularly true in view of the fact that a wrist joint has two primary rotary degrees of freedom with a complete range of combinations of the two.
Accordingly, the prime objective of the subject invention is to provide a handle having wrist bridging structure which significantly relieves physical stress on the user's wrist. A second objective is that the direction of action of a tool attached to the handle be controllable without movement of the apparatus on the user's forearm.